Metal alloy



l atented Apr. 25, 1933 UNITED STATES- PATENT OFFICE" amass vaneaevmnsn,or LA ems-s1. cnoun, AND my men, or

PARI

FRANCE IDEAL ALLOY No Drawing. Application filed August 28, 1930, SerialNo. 478,560, and in France January 7, 1980.

high coefficient of expansion A, as well as by their apparent limit ofelasticity E.

Second, that which diiferentiates them from alloys hitherto known, forexample those with a base of aluminum, copper, magnesium and manganese,is that by reason of the presence of nickel their great facility oftransformation allows of forgin swaging, rolling and wire-drawing with te greatest ease and without waste to the extent which occurs with alloyshitherto known.

\Vithin the scope of'this invention, a wide range of alloys can beobtained according to i the proportions of the constituent elements ofthe alloy.

An alloy found excellent under test is obtained according to thefollowing composit' Ion Per cent Aluminum 94. 85

Copper 3. 40 Nickel 0. 5O Chromium 0. Magnesium 0. 7 5

The proportions of the constituents may also be as follows:

Per cent Copper 1. 50 to 5. O0 Nickel 0. 25 t0 2. 5O Chromium 0. 25 tel.50 Magnesium 0. 25 to 2. 00

In the manufacture ofthese alloys there is first a basic alloyyontainingall the basic alloy is immaterial, it cbeingonly essential that thesuccessive temperatures" known, in reheatin necessary for theintroductionof each of the I constituents shall be such as to give aperfect mixture. Instead of using a basic alloy, the alloy sought can befound by employmg binary alloys of each of the additional metals, thatis to say alumino-copper, alumino-nickel, alumino-chromium.

The magnesium is introduced at the end of the operation before casting,either in the state of pure metal or in the state of binary alloy,alumino-mag'nesium, to avoid losses or recovering of the metal.

Commercial aluminum of 98%99% purity can be employed, that is to say,aluminum in which the total of iron and silicum is less than 2%, thesilicum being about 0.4%.

Better results may be obtained by using an aluminum of 99%-99.5% purity,that is, second class aluminum, containing the mini mumpercentage ofiron.

A light alloy having the composition defined above and obtained with a981%-99% aluminum will give average characteristics superior to those ofthe usual alloys.

' These characteristics may be much improved by subjecting the alloy toan appropriate thermic treatment consisting, as

500 C. (475500 composed of sodium nitrate and potassium nitrate,followed by a water bath and an aging, or more exactly a ripening, from8 to 10 days.

Under such conditions, there have been found, during mechanical testseffected with samples of metal thus treated, forged, swaged or rolled,the average characteristics Apparent elastic limit E=27 Breaking strainR=45 Coefiicient of elongation A=20% It should be particularly notedthat the role of the nickel is to. give to'the alloy its greatestfacility of transformation withoutdanger of waste, and to enable it tobe drawn into wire with the greatest facility.

It is obvious, moreover, that modifications in a salt bath at about ofdetail may be made within the scope of the l v invention and inparticularthe proportion of the constituents may vary according toWhether the metal is to be used molten, or to be swaged or rolled.

This same metal run into chills gives in 5 the rough chilled casting andwithout any treatment, the average characteristics as follows:

Apparent elastic limit E=14 to 16 Breaking strain R=19 to 24 Coeflicientof elongation A= 5 to 8% What we claim is: 1. An aluminium alloyconsisting of 94.85% aluminium, 3.40% copper, 0.50% nickel, 0.50%chromium and 0.75% magnesium.

2. A light aluminium alloy, consisting of aluminium, copper, nickel,magnesium and chromium and containing of:

Per cent Copper 1.50 to 5.00 Nickel 0.25 to 2.50 Chromium 0.25 to 1.5025 Magnesium 0.25 to 2.00

In witness whereof they aflix their signatures.

CHARLES VANGREVENYNGE.

0 HENRY ELION. 3

